Studies show that – if you are looking for a long term invest – trying to time the market always loses against "time in the market". Which means: Waiting for the "right time" to buy a stock is not a great idea as too many times you just end up with buying it at a higher price instead.
So what is a great idea then? Glad you asked!
It would be a great idea to buy a stock when you are confident it will perform great over the next years (not days or weeks). The price the day you bought it does not matter that much ten years down the road.
Now: I don't know why Rakuten lost two thirds of its value since its 2015 ATH (I did no research on the stock), but if you feel it might go back there within a few years, this could be an interesting investment.
